The human heart is a very complex organ, which relies on both muscle contraction and electrical impulses to function properly. Electrical impulses travel through the heart in a desired sequence so that the various chambers receive and pump blood in the proper order. With respect to the atria, normal excitation is propagated in a right atrium to left atrium direction via inter-atrial conduction pathways, including the coronary sinus, fossa ovalis, and Bachmann's bundle.
Abnormal inter-atrial electric flow, such as left-to-right conduction, may pose serious health risks to a patient including atrial fibrillation. Catheter ablation, that is the application of energy at a distal portion of a catheter positioned within or about the heart, or a vessel in electrical communication with the heart, to form lesions that alter conductive properties in the heart, is known for treating atrial fibrillation. Such techniques have targeted the focal trigger of an atrial arrhythmia as well as reentrant circuits in the myocardium.
Prior to the present invention, however, atrial fibrillation has not been treated by catheter ablation of one or more of the inter-atrial conduction pathways. Disturbance of electrical paths between the right and left atria has been achieved only by open surgical intervention.